The present invention relates to molded articles on pyrogenically prepared aluminum oxide, the process for their production and their use as a catalyst support or catalyst.
Pyrogenically prepared oxides are distinguished by being extremely finely divided and by a correspondingly high specific surface area, very high purity, a spherical particle shape and the lack of pores. Due to these properties, pyrogenically prepared oxides are becoming increasingly important as supports for catalysts (D. Koth, H. Ferch, Chem. Ing. Techn. 52, 628 [1980]).
Since pyrogenically prepared oxides are particularly finely divided, shaping of the powders to form catalyst supports causes some difficulties.
German OLS 31 32 674 discloses a process for the production of molded or pressed bodies in which silica sol is used as binder.
German OLS 34 06 185 discloses a process for the production of molded bodies by using glaze frit powder as a binder and glycerol as a lubricant.
These known processes have the disadvantage that the molded bodies obtained do not have the optimum properties desired, such as, for example, adequate crushing strength, for certain catalytical reactions.